Sealing means



. E. KRUEGER ALING MEANS iginal Fil ed Aug.

United States Patent Oilice 3,161,318 SEALING MEANS Rudolph E. Krueger, 2446 N. (Prchard Drive,

Burbank, Calif. Continuation of application Ser. No. 835,590, Aug. 24, 1959. This application Feb. 4l, 1963, Ser. No. 256,563 9 Claims. (Cl. L20-46) This invention is a continuation of my copending application Serial No. 835,590 filed August 24, 1959, and relates to sealing means for the closure of pressure systems including vessels and containers and particularly for the closure of such systems subjected to high pressures. This invention also encompasses a method of making sealing means.

The problems attendant upon sealing of closures in pressure systems to prevent uid leakage, become particularly aggravated under high pressure conditions. Effective sealing of closures requires that no path for fiuid flow be provided between the mating sealing surfaces. To block the minute flow passages which can exist because of irregularities in the mating sealing surfaces, the surface of a sealing means utilized to form a closure should be suiciently deformable to enable it to conform to all such irregularities. Furthermore, to provide a reusable sealing means, the sealing means must possess a degree of resiliency so that it is not permanently set once a force is removed. The more conventionalresilient materials, such as rubber, which generally meet these requirements are not usable under high pressure conditions because of the low shear strengths of such materials.

Metals have intrinsic strength properties which make theiruse advantageous as materials for construction of high pressure sealing means. Metallic sealing means become particularly necessary Where high pressures are coupled with varying extremes of temperature.- Present day technical developments result in operating environments of very high pressures under conditions of either very high or very low temperatures. The need for a reliable, tight closure under such severe operating environments demands sealing performances not found even in many metallic sealing means in prior use.

In my copending application, Serial No. 726,752, filed April 7, 1958, I disclosed a metallic sealing ring which provides effective sealing over numerous pressure cycles and under conditions of very high pressure. The metallic sealing ring therein disclosed comprises an annular spacer body and first and second annular legs extending from the spacer body toward the pressure to be sealed against. Each leg has a sealing portion divering toward a separate sealing surface, each sealing portion being adapted to provide a line of sealing contact with its respective sealing surface at the point of extreme divergence of the leg. Several embodiments of the metallic sealing ring were disclosed in the above-identified copending application.

By orienting the above-described sealing ring so that its annular legs extend toward the pressure to be sealed against, a pressure responsive sealing ring is obtained. This results because increased pressure, for example, acts to urge with increased force the sealing portion against the sealing surface along the line of sealing contact. The use of a line of sealing contact achieves significant advantages. While this line has a nite area, the area is much less than where the conventional surface-surface contact of other devices is utilized. As a result, the total pressure exerted upon the sealing ring is transmitted through the relatively small surface area forming the line of sealing contact. A high unit pressure therefore urges the sealing portion against the sealing surface. This enables intimate flow-blocking contact between the mating surfaces.

rounded edges of the flat surface.

I have now discovered a sealing ring which possesses the advantages heretofore discussed with respect to the sealing ring described in my above-identified copending application, and, in addition, possesses the advantage of simplicity and economy of construction. My present invention provides a sealing ring for a high pressure closure which comprises an annular spacer body and first and second annular legs extending in parallel spaced-apart relationship from the spacer body. Each leg has an inner and outer surface. A sealing lip projects from the outer surface of each leg at its extremity. Each sealing lip has an outer surface forming an obtuse angle with the outer surface of the leg and extending to a sealing tip. In combination with first and second joint members each having a sealing surface, the sealing tip of each sealing lip contacts a sealing surface to provide a line of sealing contact.

My invention also encompasses a combination of coatings which are particularly effective in providing a tight seal when applied to the sealing portion of the sealing ring of my present invention. The combination of coatings of my invention comprises a copper coating bonded to the outer surface of the sealing lip of the sealing ring described in the next preceding paragraph, an intermediate coating of a metal selected from the group consisting of silver and gold bonded to the copper coating, and a coating of a soft, deformable metal bonded to the intermediate coating. In the preferred embodiment of the coating of my invention, the deformable metal forming the outermost coating is tin.

The combination of coatings of my invention coacts to improve the sealing effectiveness of a sealing ring. The coating of copper provides a layer which furnishes strong adherence between the metal of the sealing ring, which is generally a stainless steel, and the outer coatings. The coating of a soft, deformable metal conforms under pressure to the irregularities of a mating sealing surface so as to block any minute flow passages. The intermediate coating of silver or gold not only protects the copper coating from oxidation but further acts as a spongy undercoating for the soft, deformable metallic coating. It has been found that where a metallic sealing ring according to my present invention has been subjected to high pressures and temperatures in excess of the melting point of the deformable metal, the latter metal was absorbed by the intermediate coating and retained in position. Under such conditions, in the absence of any intermediate coating between the coating of deformable metal and the metal of the sealing ring, the deformable metal would have flowed from the sealing portion of the ring.

While the combination of coatings of my invention has been described with reference to the metallic sealing ring of my present invention, it is to be understood that it is equally adapted to other sealing rings for high pressure closures. f

My invention further encompasses a method for coating metallic sealing rings having an annular portion diverging from an annular body of the sealing ring and having a sealing portion adapted to provide a line of sealing contact with a sealing surface at the extreme point of divergence. The method comprises the steps of lapping said sealing portion to provide a flat surface, polishing the annular portion to remove minute striations and burrs and to round the edges of the flat surface, and bonding coatings to the at surface to extend at least around the The steps prior to coating function first to remove minute burrs on the ring surface which, if not removed, would break through the applied coatings under sealing conditions and cause galling between the sealing ring and a sealing surface. Second, they function to remove discontinuities and sharp edges from the configuration of the sealing surface to Patented Dec. 15, 1964` tionl taken in conjunction which the coatings are applied. The application of coatrings over discontinuities and sharp edges enhances Vthe possibility of fluid leakage betweeny the applied coatingA v While this method'is particularly Yuseful in connection f with coating Vofthe metallic. sealing rings of my invention,

l it will be appreciated that it can `be advantageously employed in coating of surfaces of other sealing means. Furthermore, it can be utilized with coatings other than the coating of my invention, as for example, withk plastic coatings such as polytetrafluorethylene.

The .structure and advantages of the sealing ring of the present invention and the method by which it is formed will be more readily apparent from the following descripwith, the accompanying draw-l ings, in which: j s Y Y f FIG. 1 is a sectional elevation ofthe sealing ring of my present invention;

, FIG. 2 is a fragmentary sectional elevation of a cylinder and cover showing the sealing ring of my present invention prior to 'application of pressure; l o

FIG. 3 is a fragmentary'sectional elevation of the cylinder and cover of FIG. 2 showing the sealing ring fol-V lowing application 'of pressure;

. FIG. 4 is a fragmentaryk sectional elevation of one leg y of the lsealing ring shown in FIG. 1; following its formation by machining;A

FIG. 5 is a fragmentary sectional elevation of the leg shown in FIG. 4`following' lapping and polishing in accordance with the method'of my invention; andV FIG. 6 is a fragmentary sectional elevation of the legshown in FIG. 5 following application of coatings in accordance with my invention.l

ing ring 10 according to my invention isshown. Theseal- ..35 v With reference to FIG. 1,Y a sectional elevation of a seal-"V ing ring comprises an annular vspacer body 11 from which extend a rst annular leg 12 land a second annular leg 13. Q40

The annular legs areintegral with the spacer body and a 4 1 f FIG. 1 are, where appropriate, appliedlto thesealing ring in FIGS. 2.and 3.

' With referenceto FIG. 2, a-wall 32 of cylinder 30 defines an enclosure 33 which is filled with a fluid under pressure. A portion of the wall is externally threaded to receive mating internal threads of cover 31. An annular recess- 34, formedV in the upper end of wall 30, is defined in part by a rst horizontal planar sealing surface 35.

" An inside horizontal surface ofthe cover constitutes a second planar sealing surface 36'.' Sealing ring 10 is positioned in recess 34 so that sealing tips 23,-274 are in contact with sealing surfaces 34, y35, respectively. Prior lto complete tightening of cover 31 on cylinder '30, the annular spacer body of the sealing ring is not in contact with the sealing surfaces. y

With reference to FIG. 3, the sealing ring-is shown after cover 31 is fully threaded onto wall 32 of the cylinder. The application `of a force against'sealing tips 23, 24 pivotsannular'legs V12, 13 of the sealing ring about the point at which the legs join the annular spacer body. Since the ,annular groove 14 is deeperthan the radial length of the diverging portions of the legs, the legs are deii'ected like annular springs, .as shown in FIG. 3. The sealing tips are urged against the respective sealing surfaces of the cover andthe wall yand mate in a line of sealing contact with these surfaces. Pressure of the uid within enclosure 33 acts against inner surfaces 15, 17 ofl legs 12, 13,V respectively. This'total pressure is transmitted through the'line of sealing contact between the sealing tips andthe sealing surfaces. This pressure is additive to the tightening-pressure' resulting .from threading cover 31 ontowall-SZ of Athe cy1inderl In.' this connection,"the V'annular spacer body acts'vv as a stop limiting the degree to which the cover is threaded lonto the cylinder.

are removed, the yresiliency of the annulary legs restores are in a` spaced-apart parallel relationship so as to definel f a hollow or annularv groove 14 between them. Leg 12y has an inner surface 15 defining one side of the vhollow and an outer surface 16. Leg 13 has anY inner surface 1-'7 dening another side of the hollow and an outerr surface 18. Outer surfaces 16 and 18 of legs 12 andY 13, respectively, co-extend in the same plane as the outer Surfaces of the annular spacer body.

Near th'eextremi'ty of leg 12 a sealing lip or annular portion 19 projects from the outer surface of the. leg. f.

Sealing lip 19 has an outer surface 20 which forms an obtuse angle with the outer surface of the leg. Near the `extremity of leg 13, a sealing lip or annular portion 21 projects from the outer surface of leg 13 and has an outer surface 22 which forms an obtuse angle with the outer surface ofleg 13. Preferably, the angle formed between the outer surface of each sealing lip and the outer s ur-A face of its associated leg is between 155 and 165".y EachV sealing lip has a conguration which in cross section is substantially a right triangle'. The hypotenuse of the the sealing lips to substantially they unstressed position shown inFIG'. 2. In this connection, the line of sealing contact enables design calculations for determining the proper amount of projection of thesealing lip above Athe outsidesur'face of its associated leg so as to provide a reuseable seal even yfollowing plastic deformation.l A

lline of sealing contact establishes a definite distance from the spacer body to the point of sealing contact. `Through l Vthe ratio of the product of the unit pressure and saidl dis- ,surfaces iof the legs is from 0.003 to 0.005 inch.

tance tothe product ofthe varea 4of sealing contact and the moduluso:` elasticity of the'sealing ring material, the

amount of spring return can be calculated.

` It is to be understood that FIGS. 1-3 have been somewhat exaggerated for-purposes of clarity inrconnection with the explanation ofthe structure and behavior of the sealing Vring of my invention. In its preferred form, the extent of projection of the sealing tips above the outer It can Vbe seen, therefore, that the degree of pivoting required to achieve the stressed position of the seal shown in FIG. 3

right" triangle is the'outer surface of the sealing -lip and the altitudel of theright triangle is in the same plane as` the outer4 surface of its associated leg. The angle formed opposite the altitude represents the'V extreme point ,of projection of the `sealing lip. For sealing lip 19, this point is sealing tip 23. For sealing lip 21, this point is sealing tip 24. As shown in FIG. l, the radi-al length of eachof the outwardly diverging portions 19 and 21 is less than the V.

radialfdepth of the annular groove in the body.

With respect to FIGS. 2 and 3, a/sea'ling ring, identical to that described with'refereric'e to FIG. l, is shown in a position to provide a closure between a cylinder30 and a cover31, a fragmentary portion of each being shown.

I'Ifhe reference characters applied to the sealing ring ofv ence to FIG. l.

is substantially less than wouldV v,appear Vto be `the case from the drawings.

The sealingring of my invention is preferably made l.from metals such as stainless steel or bronze. f It is formed by machining. Where a coating of a 'deformable mate-- rial is to be lapplied to the sealing portion of the sealing ring, I have found an improved method for treating the surface of the. sealing ring to which thev coating is applied. I have further found .an improved combination of coatings for high pressure sealing effectiveness.

To illustrate the method foffmyV invention and the combination yof coatings of` my invention, FIGS. 4-6 show in `section a fragmentary portion of an Vannular leg 40 of a sealing ring identical `to that described with refer- Y y The leg has aninner surface 41 and an outer surface 42. y A sealing lip 43 projects from the outer surface of the leg. An outer surface 44 of the sealing lip intersects outer surface 42 of the annular leg at the discontinuity identied by the reference character 45. A sealing tip 46 is the extreme point of projection of the sealing lip.

FIG. 4 represents leg 40 and sealing lip 43 of the sealing ring following formation by machining and prior to treatment by the method of the present invention. FIG. 5 represents the leg and sealing lip following lapping and polishing according to the method of the invention. FIG. 6 represents the leg and sealing lip following application of the combination of coatings according to the invention.

With reference to FIG. 4 particularly, sealing tip 46 of the sealing ring is sharply defined. While this configuration represents an advantageous embodiment of the sealing ring of my invention, some difficulties are present in machining the sealing tip to the proper degree of definition. I have found it preferable, therefore, to produce a fiat surface at the sealing tip by lapping the tip through the use of flat Carborundum stones or grit.

Accordingly, as a first step of the method of the present invention, the sealing tip is lapped to produce a at surface as generally shown by reference character 46A in FIG. 5. Preferably, the width of the flat surface is from 0.003 to 0.010 inch. This at surface enables attainment of a line of sealing contact. In an unstressed condition, such as the condition of the sealing ring shown in FIG. 2, the flat surface of each sealing lip is in contact with its respective sealing surface. In a stressed condition, such as the condition of the sealing ring shown in FIG. 3, pivoting of the annular legs, as previously described, results in pivoting of the fiat surface so that the edge of each ilat surface which is nearest the annular spacer body is urged in a line of sealing contact' with the sealing surface.

As a second step of the method of the present invention, outer surface 44 of the sealing lip and flat surface 46A are polished with line sandpaper to remove any ridges, burrs or striations existing in these surfaces. While polishing of outer surface 44 of the sealing lip may be extended to remove discontinuity 45 at the point of intersection between outer surface 44 of the sealing lip and outer surface 42 of the annular leg, as shown in FIG. 5, this is not essential to the practice of the method of my invention. It is suflicient if polishing of outer surface 44 is carried out' to some point on said surface substantially removed from the inner edge of llat surface 46A. The polishing is also carried out to round the edges of flat surface 46A, as particularly shown in FIG. 5. Polishing in the manner herein described acts to remove ridges and burrs as well as sharp edges, the presence of which, under conditions of high pressure and temperature, would enhance the possibilities of galling of sealing surfaces and fluid leakage.

A sealing surface treated as hereinbefore described may be coated with any suitable deformable material which is bondable to the base metal of the sealing ring. When the combination of coatings of my invention is applied, a coating of copper 47 is bonded to the outer surface of the sealing lip. As shown in FIG. 6, the coating extends past the blended point of intersection between outer surface 44 of the sealing lip and outer surface 42 of the annular leg and around the outer rounded edge of flat surface 46A. Thereupon, an intermediate coating of silver or gold 48 is bonded to the copper and a coating of a soft, deformable metal 49 is bonded to the intermediate coating. While in practice it maybe convenient to coat the entire sealing ring in the manner described, it is only essential that the coating cover liat surface 46A and extend around the rounded edges of said flat surface.

The combination of coatings of my invention may be deposited electrically or chemically by conventional methods. The soft, deformable, metallic coating is preferably tin, although lead or bearing metal alloys may be used. The thickness of the copper coating is preferably between .0002 and .0003 inch; the thickness of the silver or gold coating is preferably about 0.00008 inch; and the thickness of the soft, deformable, metallic coating is preferably between 0.0001 and 0.0002 inch.

While the sealing ring of my present invention, treated by the method of my invention and lhaving the combination of coatings of my invention, is a reuseable sealing means providing tight, repetitive sealing under conditions of high pressure and varying extremes of temperature, it is to be understood that the method and combination of coatings may be advantageously utilized individually with other sealing means.

I claim:

1. In a high pressure closure, the combination comprising `first and second ljoint members each having substantially planar sealing surfaces adapted to be moved toward each other from an initial position to a linal operative sealing position, an annular metal spacer body between the first and second joint members, first and second annular legs extending in parallel spaced-apart relationship from the spacer body, each leg having an inner and g outer surface, the inner surfaces of the legs being parallel, the outer surfaces of the legs being parallel and each having a portion diverging toward a separate sealing sutrface to form a sealing lip projecting from the outer surface of each leg at its extremity, said sealing lip having `an outer surface forming an obtuse angle with the outer surface of the leg and extending to a sealing tip when the sealing surfaces are in the initial position, said sealing tip of each sealing lip contacting a sealing surface of the first and second joint members respectively to provide only a line contact in final operative sealing position.

2. In a high pressure closure, the combination comprising first and second joint members each having substantially planar sealing surfaces adapted to be moved toward each other from an initial position to a linal operative sealing position, an annular metal spacer body between the first and second joint members, first and second annular legs extending in parallel spaced-apart relationship from the spacer body, each leg having an inner and outer surface, the inner surfaces of the legs being parallel,

the outer surfaces of the legs being parallel and each having a portion diverging toward a separate sealing surface to form a sealing lip projecting from the outer surface of each leg at its extremity, said sealing lip having an outer surface forming an obtuse angle with the outer surface of the leg and extending to a sealing tip when the sealing surfaces are in the initial position, the tip including a flat surface, the edge of said lllat surface nearer the spacer body contacting a sealing surface of the rst and second joint members respectively when the irst and second annular legs are stressed by bringing the `iirst and second joint members toward each other to provide only a line contact in lfinal operative sealing position.

3. Apparatus in accordance with claim 2 including a copper coating bonded to the outer surface of the sealing lip to extend at least around the sealing tip, an intermediate coating of a metal selected from the group consisting of silver and gold bonded to the copper coating, and a coating of a soft deformable metal bonded to the intermediate coating.

4. Apparatus according to claim 3 in which the soft deformable metal is selected from the group consisting of tin and lead.

5. Apparatus according to claim 2 in which the edge of the flat surface nearer the spacer body is rounded where the outer surface of the sealing lip intersects the flat surface, a copper coating bonded to said flat surface to extend at least around its rounded edges, an intermediate coating of a metal selected from the group consisting of silver and gold bonded to the copper coating, and a coating of a soft deformable metal bonded to the intermediate coating.

. 7 n 6; Apparatus according to claim 2 irrwhich the deformable metal is tin. l

7. A metallic sealingring adapted to t between a pair Y of sealing surfaces and be subjected to stressed and unstressed conditions, theV ring including an annular metal body, a pair of legsextending from the body in` a direc- 'tion generally parallelto the plane of the body, each leg Y having diverging portions with outer surfaces, the outer surfaces divergingfrom each other'and extending toward a respective sealing surface atan acute angle'iin the unstressed condition, 'each of the outer surfaces appearing as a'straight line when the legslareviewed in cross section, a separate flat annular portion on the extremity of the diverging portions of each leg and adjoining the respective said outer surfaces, the edge ofeach at ,surface nearer the spacer body being rounded where it joins its respective rsurfaces diver'ging from each other and extending ltoward t a respective #sealing s'urface at 'an acute angle inthe -unstresse/d condition, each of the outer surfaces appearing as a straight line when the legs are viewedr in cross section outer surfaceto make only line contact with? the adjacent body, a pair of annular legs extending from the bod'y in the same general direction, each leg having a diver'ging annular portion with an outer annular surface, the outer taken in a plane normal to the annular' body, a separate flat annular portion on ythe' extremity of theHiver-ging portions of each leg and adjoining a respective vsaid outer surface, each annular at portion appearing asia straight line when viewedkin cross section taken in a plane normal to the annular body, the edge of each dat vsurface being' rounded where it joins its respective outer surface to make only line contact with the ladjacent respectivetsealing'surface in inal operative sealing position, and alayer of coating material o'n ea'ch said rounded part, thecoating being softer than the metallic body.: Y Y

References lCited inthe rfile of this patent p VUNITED STATES PATENTS 1,339,636 Y i i .Tulloch May 1l, 1920 2,641,381 Bertrandfune June 9, 1953 A 2,898,000 Haney v v Aug.'4, 1959 3,042,248 v Krueger .V July 3, 1962 I FOREIGN vPATENTS 63,947 France May 4, 1955 (lst Addition 1,078,364) 

1. IN A HIGH PRESSURE CLOSURE, THE COMBINATION COMPRISING FIRST AND SECOND JOINT MEMBERS EACH HAVING SUBSTANTIALLY PLANAR SEALING SURFACES ADAPTED TO BE MOVED TOWARD EACH OTHER FROM AN INITIAL POSITION TO A FINAL OPERATIVE SEALING POSITION, AN ANNULAR METAL SPACER BODY BETWEEN THE FIRST AND SECOND JOINT MEMBERS, FIRST AND SECOND ANNULAR LEGS EXTENDING IN PARALLEL SPACED-APART RELATIONSHIP FROM THE SPACER BODY, EACH LEG HAVING AN INNER AND OUTER SURFACE, THE INNER SURFACES OF THE LEGS BEING PARALLEL, THE OUTER SURFACES OF THE LEGS BEING PARALLEL AND EACH HAVING A PORTION DIVERGING TOWARD A SEPARATE SEALING SURFACE TO FORM A SEALING LIP PROJECTING FROM THE OUTER SURFACE OF EACH LEG AT ITS EXTREMITY, SAID SEALING LIP HAVING AN OUTER SURFACE FORMING AN OBTUSE ANGLE WITH THE OUTER SURFACE OF THE LEG AND EXTENDING TO A SEALING TIP WHEN THE SEALING SURFACES ARE IN THE INITIAL POSITION, SAID SEALING TIP 